Dummies Guide to Travel Insurance

lostinfrance72

For the first time in many many years, we are taking a long-haul family trip. We have not booked through a travel agent - the flights have been booked directly with the airlines, and the accommodation through Booking.com .
I have been looking at various travel insurance packages / websites, and I am confused! Many of them don't seem to include cancellation - which seems like a no-brainer to me. My main (non-medical) concern is if the airline cancels the flights into Singapore (due to coronavirus) and this has a knock-on effect on all the (non-refundable) accommodation and activities that have been booked. I'll outline our situation and maybe some kind soul could tell me what we should be looking for in a travel insurance policy - and what fish-hooks I should be looking out for:
4 people: 2 adults, 2 children 9 and 12yrs.
Flying Europe to Singapore, travelling to Malaysia and Indonesia, then back to Singapore and home. 3.5 weeks total travel time. Originating in France (where we live) but we are British. Travelling in July-August 2020.
Everything paid for using a credit card (I have checked with the credit card company - they have told me that protection is very limited, and not to be relied on in the event of cancellation of the flights). 
No existing medical conditions. 
Will be doing "active" sports include scuba diving. 

Thanks for any advice.